The purpose of this study is to describe the pelvic floor musculature (PFM) characteristics in women with genuine stress urinary incontinence (GSUI) as compared to a control group of normal, health nulliparous women with no history of GSUI. The following aims will be tested: Aim 1: To describe the characteristics of pelvic bone structure (geometry) in women with GSUI as compared to nulliparous women with no history of genuine stress urinary incontinence (GSUI). Aim 2: To describe the differences in the structural anatomy (morphology) of the PFM including muscles, fascia and ligamentous structures at rest in women with GSUI as compared to healthy, normal nulliparous women. Aim 3: To describe the differences in function and contractility of the PFM in women with GSUI as compared to healthy, normal nulliparous women. Aim 4: To describe the effects of controlled PFM relaxation following contraction in regard to regress of strain subsequent to PFM contraction in women with GSUI as compared to healthy, normal nulliparous women. Background and Significance: Urinary incontinence (UI) affects approximately 14 million individuals in the United States; the majority of these are women. Genuine stress urinary incontinence is involuntary urine leakage during coughing, sneezing, or other physical activities that increase intra-abdominal pressure. Development of GSUI in women is multi-factorial including childbirth, increased age, and genetic influences. The mechanism(s) of improvement induced by rehabilitative exercises of the PFM have not been adequately described. Method: A descriptive study design will be used to describe pelvic bone structure (CT scan) and pelvic muscle structure and dynamic function (NMRI) in women with GSUI compared to nulliparous controls. Statistical Analysis: Descriptive statistical analysis will be used to obtain frequencies and percents (nominal-level variables), and means and standard deviations (interval/ratio level variables). This analysis will provide an estimate of effect sizes and sample size requirements for testing differences in future studies.